Mold form for circular concrete walls



June 30, 1936. w JENNINGS 2,046,123

MOLD FORM FOR CIRCULAR CONCRETE WALLS Filed Jan. 7, 1955 0O QO /2 00 (DOM131 00 CO I @y W i/3% Patented June 30, 1936 UNETE STATES PATENT OFFEQEMOLD FORM FOR CIRCULAR CONCRETE WALLS Application January 7, 1935,Serial No. 613

2 Claims.

In the art of mold forms for concrete walls it is at the present timecustomary to provide such mold forms consisting of rectangular panelswhich may be made of sheet metal but 5 which are strengthened andreinforced on all edges by braces to thereby give rigidity to the form.It is also customary to provide in these flanges symmetrically arrangedcentering openings so that the form members may be securely 1e andrigidly clamped together at their edges by means of a centering pin andclamp device. One instance of such form members and centering pin andclamping device is illustrated in my copending application Serial No.673,214, filed May 27, 1933.

With form members of the kind just mentioned, and in the event that acircular concrete wall is to be molded, it is the present custom toprovide specially designed mold forms for this purpose and not to employrigid rectangular mold forms in such circular construction.

The object of my invention is to provide a supplemental mold form memberof extremely simple and inexpensive construction, and designed to co-actwith, and form an integral part of, a series of said rigid rectangularmold forms, and at the same time render the entire mold, consisting of aseries of said rigid forms and a series of my improved auxiliary formmembers, capable of being bent at the auxiliary form members, so thatthe entire wall structure for the form may be shaped into a circle ofalmost any desired diameter, so that the major portion of a mold formfor either a straight wall or a circular wall may be composed of saidrigid rectangular form members, thereby effecting great economy in thefirst cost of the equipment necessary for the operator to build eitherstraight or segmental walls, and greatly reducing the amount of time andlabor necessary to erect mold forms for circular walls of differentdiameters.

A further object of my invention is to provide an accessory mold formmember designed to be used in the same manner as that before mentioned,and shaped to form a mold form in a circular and cone shaped manner.

My invention consists in the construction of said auxiliary mold membersand the manner in which they are combined with a series of rigid formmembers, and whereby the objects contemplated are attained, ashereinafter more fully set forth, pointed out in my claims, andillustrated in the accompanying drawing, in which:

Figure 1 shows a side elevation from the outer side of the mold forms,illustrating two ordinary rigid mold forms with my improved auxiliarybendable mold form inserted between them and firmly secured thereto.

Figure 2 shows an edge elevation of the perforated flange of myauxiliary form member.

Figure 3 shows a top or plan View of a mold having two spaced apartwalls to receive concrete, and illustrating my improved auxiliarybendable mold members in position in said walls, arranged to constructsubstantially circular walls,

Figure l shows a perspective view of a centering pin and fonn clampingdevice of the kind used in connection with my improved mold members; and

Figure 5 shows a perspective view of a modified form of my improvedauxiliary form member shaped for use in connection with cone shapedcircular walls.

Referring to the accompanying drawing, I have used the numeral ill toindicate generally an ordinary rectangular metal form member having atall four edges thereof an outwardly extended flange ll. These flanges Hare preferably provided with a series of symmetrically arrangedcentering openings 12.

In each of the mold form members ll) there is a series of slots l3designed to receive spacing rods M, which rods are extended through theopenings of one of the form members it and also through a similaropening in the opposed form member It], as illustrated in Figure 3, andpins l5 are extended through the outer ends of said spacing bars tothereby hold two opposed mold forms in properly spaced apart positionand against outward movement such as would be caused by the pressure ofthe concrete between the walls.

For the purpose of connecting together the flanges I l of two adjacentmold forms, it is now customary to use a combined centering pin and rclamping device, such, for instance, as illustrated in Figure 4 andwhich consists of a handle l6 having a pointed centering pin ll at oneend thereof, and two rigid spaced apart clamping jaws l8 projecting fromthe central portion of said handle.

In practice the two mold forms are placed in position substantiallyparallel with each other, then the operator grasps the handle it andforces the centering pin ll through the openings !2 of two adjacentflanges II, and then moves the clamping jaws I8 to position for engagingthe outer surfaces of two adjacent flanges, so that by this means thetwo adjacent mold forms are rigidly locked together.

For the purpose of utilizing these same rigid mold forms in a circularor segmental concrete structure I have provided an auxiliary mold formmember, preferably made of the same kind of sheet metal as the rigidmold form members and comprising a relatively narrow body portion l9 andtwo flanges 2i! extended at right angles thereto. There are no flangesat the top and bottom of the auxiliary member, and the entire spacebetween the flanges 28 is free and unobstructed. These flanges '29 areprovided with perforations 2!, in the manner shown in Figure 2, similarto the perforations l2 inthe rigid forms, and they are connected withthe adjacent flanges of the rigid forms by means of the centering pinand clamping device illustrated in Figure 4, or in the same manner inwhich the flanges of the rigid form members are connected together.

With my improved auxiliary mold form mem-. her, and assuming that it wasclamped in the manner described, between two rigid form members, then,asrillustrated in FiguregS, the two rigid form members may be readilyand easily moved to the position shown Figure 3, thus bending the bodyportion l 9 of the auxiliary form member, and this may be bent to. anarc of almost any desired size, and at the same time the complete moldform will have all the necessary rigidity and strength.

Obviously, when a circular structure is to be built, the inner 'formmember will be of less diameter and consequently shorter in length thanthat of the outer form member, and, yet, his necessary and desirablethat the inner rigid panels should he arranged substantially in lineradially with the outer rigid panels, so that the sp cing rods l may besuccessfully employed.

I have found in practice, however, that it is not essential that thesespacing rods be exactly radial,

, and for the purpose of bringing them, in a circular wall construction,to the desired position for successful operation, I have. found, inpractice, that at intervals throughout the outer wall I may employ two.of the narrow auxiliary bendable mold form members, as illustrated atthe topof Figure 3.

When it is desired to have. a circular cone shaped structure I employ amodifiedfcrm of my invention, illustrated in Figure 5., in which thisauxiliary bendable mold form member is shown to be tapered in widthfrom'a maximum at one end, towards the other end, and I have found inuse that with this tapered member a circular cone shaped wall may bereadily, quickly and easily constructed.

In practical use with my. invention I havev demonstrated thatconsiderable economy is efiected, because a contractor need only ship tothe point of erection a desired quantity of rigid rectangue lar formsand a relatively small and inexpensive quantity of my improved auxiliarybendable form members. Then. at places where the concrete walls are tobe relatively straight the rigid form members are employed in the usualmanner, and at the. places in the structure. where. the. walls are to becircu ar or segmental or tapered, I erns ploy comparatively small numberof my improved auxiliary bendable mold members in the manner described;and since these. auxiliary mold members are provided with the sameflanges and perforations as the rigid mold members, the same centering.and clamping devices may be employed.

improved bendable members may be reused just as much as the rigid formmembers, be-- cause when taken apart the bendable portion may be readilyand easily straightened and again rebent, if necessary, at greater orless are.

When it is desired to make a. cone shaped concrete structure,the taperedbendable mold forms are employedin the same manner as aforementionedwith regard to the rectangular. andauxiliary mold members.

Another advantage of my improvement in mold forms is, that the auxiliarypanel members may be freely bent'in both directions, hence, the samekind of auxiliary panels may he used on the inner surface. of a circularwall and on the outer surface of a circular wall, dueto the fact thatthere are no transverse braces on said auxiliary panel members-Furthermore, by making the auxiliary panel members relatively narrow andinserting them between standard sized panels the upper and lower flangesof the adjacent standard sized panels may be clamped together in theusual manner and will form a sufliciently rigid mold without anyattachment at the top and bottom of the auxiliary panel members.

' I claim as my invention:

1. In a mold for curved concrete forms, the combination of two formpanels, each made of sheet, metal with its. edges bent outwardly at substantiallyright angles tothe frame body and connected together at thecorners for forming sub stantially rigid panels, said flanges beingformed with pin receiving openings, a relatively narrow panel memberformed of sheet metal and having its side edges formed with outwardlyextended flanges, the body portion between said flanges being free fromtransverse braces and readily bendable in reverse directions betweensaid flanges, the openings of the flanges of the narrow panel beingarranged to align with the said openings in the side flanges in therigid panels, and pins passed through said openings in said flanges foraligning; the panels.

2. In a mold for curved concrete forms, the combination of two formpanels, each made of sheet metal with its edges bent outwardly atsubstantially right angles to the frame body and connected together atthe corners for forming substantially rigid panels, said flanges beingformed with pin receiving openings, at relatively narrow panel memberformed of sheet metal and having its side edges formed with outwardlyextended flanges having pin openings, the body portion between saidflanges being free from transverse braces and readily bendable inreverse directions between said flanges, the openings of the flanges ofthe narrow panel being arranged to align with the said openings in theside flanges in the rigid panels, pins passed through said openings insaid flanges for aligning the panels, and clamping means applied to saidflanges for'firmly holding 6 7 WILLIAM 7 JENNINGS.

